A Denver Sheriff's deputy accused of helping a dangerous felon escape the Downtown Denver Detention Center drove him to Thornton, then returned to the jail, where he faced questions from investigators, law enforcement sources said Monday.

Matthew Andrews, 36, a two-year-veteran of the sheriff's department, was arrested and now faces felony charges that he aided in the escape of Felix Dino Trujillo, 24, who walked out of the jail about 7 p.m. Sunday wearing a deputy's jacket. Trujillo remained at large as of Monday night, Denver police said.

It was the first escape from the city's new detention center, which opened in 2010, and was also the first time in recent memory that a Denver deputy was accused of aiding an escape, said Lt. Matt Murray, a Denver police spokesman.

Felix Trujillo. (Colorado Department of Corrections)

"This is from the most secure facility in the city. ... Without the deputy's help, he could not have gotten out," Murray said. "This is very, very rare."

Authorities found no weaknesses in the jail's security systems, Sheriff's Maj. Frank Gale said. Internal affairs investigators were studying surveillance footage from the jail's many cameras to determine how the escape played out and whether others inside or outside the jail were involved.

Gale said an inventory revealed Trujillo did not take a deputy's gun or police radio.

"He may have a weapon. ... but he didn't get it from the Denver Sheriff's Department," Gale said.

Trujillo's criminal history underscores his danger to the public, Murray said. Trujillo was awaiting sentencing for an August robbery in which police said he was one of three people who held up the residents of a southwest Denver home for a kilo of cocaine. Trujillo pleaded guilty to a lesser charge of burglary with a weapon, court records show.

In 2011, he was charged with escaping from an Adams County halfway house, where he had been serving time for obstructing justice.

After returning to the jail, Andrews was taken to police headquarters and questioned for several hours before being arrested. He posted $10,000 bond and was released from a detention center in Broomfield on Monday.

Andrews' family could not be reached for comment, and he had not officially retained an attorney.

Andrews, who served general security duties in the jail and was working Sunday night, told police that Trujillo had made threats against him, according to sources who spoke to The Denver Post on condition of anonymity.

An investigation was already underway by the time Andrews returned to the jail, police said. Officers were told to be on the lookout for Trujillo about 9 p.m., two hours after he left. Murray would not say what happened during that time.

Police described Trujillo as 5 feet, 6 inches tall, 140 pounds with tattoos on his neck and chest. They urged anyone with information about his whereabouts to call 720-913-2000 or 911.

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